94 6spd. HISTORY:

About 3 years ago, the car wouldn't start after a drive ( no cranking nothing). Had it towed to a shop and they said $1,900 and it will be running. Said NO and had it towed to my house. At this time I was only able to change oil and breaks. I broke it down...changed opti, plugs, wires, water pump ect..and still no start. I changed the Ignition control module and it fired right up.

Years down the road. I was getting engine code 42 ( faulty ground concerning ICM) and it would shut off and turn on whenever it wanted. After my rebuild 2k miles ago, the light has been staying on 24/7 an stored as a history code. It would NOT erase out of PCM no matter what I did. I even checked all wiring and replaced connectors. BUT I never had a no start issue for years. Well just the other day the car wouldn't start. I knew it was the ICM so I let if cool off for a couple hours and it fired right up.

I went to autozone and got their $69 dollar ICM with life time warranty and put it in. I have NO check engine light and I have not had it pop on and even not let the car start in over 150 miles.

There is a lot of talk about ICM problems with no fixes or talk about what fixed an issue. I am letting people know what fixed my issue.

 

Very cool fix for very little $$$. Dont hear too many stories like that.

 

ICM overheating is a non stop problem. I've even considered adding a cpu fan to keep the temp down.

 

well years ago, my icm would over heat no problem ok just replace it. But it was showing a code that would NEVER go away. So to clear the code really made me less stressed.

 

Compatibility in electronics is sometimes can make for strange problems. Many times the fix is simple but not obvious. Some electronic parts have a correct part number but might not have the exact specifications. That something you can't visual see and might not be able to measure either. Circuits, parts, computer software i.e. ECM/PCMs look for specific parameters when operating in a built in test mode. When things are not the way as they expect it, then it raises a flag.

What kind or brand of ICM did you remove?

Got A/C.

 

still no AC but its soo cold right now I wont be able to use it for a couple months..

I believe I pulled off an AC Delco...I will post a pic tomorrow.

 

It is not a bad idea to change the coil when you have an ICM go bad. Often they go bad because the attached load is too great. The load being the primary windings of the ignition coil and if shorted will present an overload situation even though the coil sort of works enough to run the car. Having 2 go bad would be a very large red flag for me.
Dave

 

i have a similair story. my icm went bad one day while driving, car backfired and then shut off and wouldnt start. i replaced with an expensive bosch icm and car started right up but had a check engine light code 42. it would go away once car was warmed up but from 0-185 degress i had the light. replaced it with a cheap advance auto parts icm and light went out and iv never had a problem since then.

 

I wish I only replaced 2 ICM's...Since I first had the problem almost 4 years ago, I have replaced probably 5. Since my new one had a warranty, if it dies, I will replace it and get a new coil as well.

 

are you remembering to use the heat sink compound on the back of the icm? could there possibly be a reason that yours are getting too hot? maybe dirt and grime built up around the area?

 

Can they do a test on that at the parts store or do you buy the part and hope for the best ?

 

Autozone I believe is the only store able to test an ICM. But from my past trails, they must run their test more than 6 times to get the ICM hot enough to show a failing ICM. I put the good grease on the ICM's from radio shack !!

 

Thanks. I dont have an LT1 but do work on them from time to time.

 

Do ya think?

 

lol..I hope for the best anytime I buy something..